Corneal cross-linking for treatment of keratoconus relapse in post-keratoplasty eyes

PURPOSE

Keratoconus relapse after penetrating keratoplasty is a rare condition that may result in severe visual deterioration and corneal graft thinning. Therefore, treatment to stabilize the cornea should be considered. The purpose of this study was to evaluate the safety and efficacy of Corneal Cross-Linking (CXL) in eyes with relapse of keratoconus after penetrating keratoplasty for keratoconus.

MATERIALS AND METHODS

A retrospective review of eyes that developed keratoconus relapse following a penetrating keratoplasty and treated with CXL. The main outcome measures were change in maximal keratometry (Kmax), best-corrected distance visual acuity (BCVA), thinnest corneal thickness (TCT) and central corneal thickness (CCT), and complications.

RESULTS

We identified 10 consecutive eyes of 9 patients. Preoperative median BCVA before the CXL and 1 year after the CXL procedure remained stable (p = 0.68). The median (IQR) of Kmax improved from 63.2 (24.9) D before the CXL procedure to 62.2 (27.1) D at 1 year postoperatively (P = 0.028). Median TCT and CCT also remained with no significant change 1 year after CXL. No complications were noted following the procedure.

CONCLUSION

CXL in eyes with keratoconus relapse after keratoplasty is a safe and effective procedure enabling not only visual stabilization but also might bring keratometry improvement. Routine follow-up after keratoplasty should be performed for early detection of keratoconus relapse and CXL is timely advised when such a relapse is documented.

The Change in Corneal and Conjunctival Sensation Following Pterygium Surgery

BACKGROUND

The cornea is one of the most densely innervated in the body. Pterygium surgery includes removal of the pterygium tissue from the cornea and conjunctiva followed by autologous conjunctival grafting.

OBJECTIVES

To examine the change in corneal and conjunctival sensation post-pterygium surgery.

METHODS

This prospective study included patients with primary pterygium. We collected and analyzed demographic data, visual acuity (VA), refraction, quantified sensation, and corneal tomography. Comparison in sensation in the cornea, conjunctiva, and conjunctival autograft was recorded the day of surgery and at least 6 months postoperatively.

RESULTS

Nine patients participated in the study. Mean follow-up time was 9 months (9  3.3, 6-12.4). No complications were documented during or following surgery and no recurrences were found. Statistically significant increases in corneal sensation in the nasal corneal and in the nasal conjunctival areas were noted by the end of follow-up compared to before surgery (P = 0.05, paired samples t-test). There was a significant correlation between the increase in nasal corneal and conjunctival sensation with improved Schirmer testing outcomes and tear break-up time after surgery (P = 0.05, P = 0.01, Pearson correlation). There was a positive correlation between the changes in nasal corneal sensation after surgery and improved changes in VA (P = 0.02, Pearson correlation).

CONCLUSIONS

We found improvement in sensation 9 months after pterygium surgery, which may be due to reinnervation of the cornea and conjunctival autograft from the neighboring non-injured nerve fibers. Larger studies with confocal microscopy should be conducted for further analysis.

Accelerated Versus Standard Corneal Collagen Crosslinking in the Treatment of Keratoconus: One-Year Results

BACKGROUND

Keratoconus is a non-inflammatory disease characterized by progressive corneal steepening, which leads to decreased visual acuity secondary to high irregular astigmatism.

OBJECTIVES

To compare the one-year outcomes of accelerated vs. standard collagen crosslinking (CXL) in the treatment of keratoconus.

METHODS

A database search of patients who underwent CXL from 2009 to 2017 was conducted at the cornea clinic at Sheba Medical Center. Charts of 99 adult patients (124 eyes) were reviewed. All patients were diagnosed with keratoconus. Main outcome measures were change in keratometry, uncorrected visual acuity (UCVA), and best-corrected visual acuity (BCVA.

RESULTS

We evaluated outcomes in two groups: CXL with standard (3 mW/cm2 for 30 minutes) vs. the accelerated (9 mW/cm2 for 10 minutes) protocol. There were no significant differences between the groups with regard to BCVA, UCVA, and mean spherical equivalent (P =0.83, 0.0519, 0.181, respectively). The corneal thickness in the center and thinnest location were higher in the accelerated group than the in the standard group (P = 0.126). Complication rates did not differ between the two groups.

CONCLUSIONS

Accelerated and standard CXL are both safe and effective techniques. Accelerated CXL confers the added benefit of being a faster procedure to both patients and surgeons.

Topical Estrogen Therapy for Hyperopia Correction in Vivo

Purpose

In vitro studies found that 17β-estradiol (estrogen) modulates corneal biomechanical properties and reduces tissue stiffness. Therefore we hypothesized that topical estrogen might affect the refractive properties of the cornea, inducing a myopic shift.

Methods

Twelve female New Zealand white rabbits 16 weeks old were used. The rabbits were randomly divided to either the treatment group receiving 1.5% (w/v) estrogen eye drops or a control group receiving vehicle only (n = 6 each group). Both groups were given drops (50 µL) to the right eye every 12 hours for 35 days. Ocular examination, pachymetry, intraocular pressure (IOP), keratometry, and refraction were evaluated at baseline and on a weekly basis.

Results

No significant differences were observed between the two groups at baseline in all outcome measures. Both groups displayed corneal flattening and a hyperopic shift. However, the change rate was slower in the treatment group. Repeated measurements analysis revealed a statistically significant difference in keratometry readings between groups (P = 0.034) with steeper keratometry by up to 0.6 diopters in the treatment group. The difference between the two groups diminished and became statistically insignificant after treatment cessation. No significant changes were observed in IOP and pachymetry throughout the study period. No side effects were observed in either group.

Conclusions

Estrogen eye drops induced a myopic shift in keratometry readings. These results suggest that corneal refractive power might be manipulated pharmacologically. Further studies on the physiology behind this change are warranted to facilitate a pathway for development of novel pharmacologic treatments to correct refractive errors.

Multimodal Assessment of Corneal Erosions Using Optical Coherence Tomography and Automated Grading of Fluorescein Staining in a Rabbit Dry Eye Model

Purpose

To evaluate the potential use of anterior segment spectral domain optical coherence tomography (AS-SD-OCT) combined with an automated grading of fluorescein staining for assessment of corneal erosions in a rabbit short-term dry eye model.

Methods

Twenty-one New Zealand white rabbits were anesthetized and eyes were kept open for 140 minutes to induce acute corneal desiccation. Rectangular scans of the cornea were performed using Spectralis AS-SD-OCT. Total corneal thickness, corneal epithelial thickness, and the percentage of epithelial erosion area (PEEA) were evaluated. Corneas were stained with fluorescein and graded automatically using EpiView and semi-automatically using ImageJ. Spearman's rank-order correlations were calculated to compare the AS-SD-OCT PEEA and the two corneal staining scores.

Results

Eye desiccation resulted in corneal epithelium erosions that covered 0.67% to 14.2% of the central cornea (mean ± SD: 3.95% ± 3.2%) by AS-SD-OCT. The percentage of corneal area positively stained with fluorescein ranged from 0.24% to 38.01% (mean ± SD: 12.24% ± 9.7%) by using ImageJ, correlating with the AS-SD-OCT PEEA (Spearman's ρ, 0.574; P = 0.007). The EpiView score ranged from 0.5 to 10.17 and was better correlated with the AS-SD-OCT PEEA score (Spearman's ρ, 0.795; P = 0.000017).

Conclusions

Our study suggests that multimodal analysis of AS-SD-OCT and grading of fluorescein staining using EpiView software may enable quantitative assessment of corneal epithelial erosions in a rabbit short-term dry eye model.

Translational Relevance

This multimodal imaging analysis may be applied for evaluation of superficial punctate keratitis associated with dry eye.

Contralateral eye comparison of descemet membrane endothelial keratoplasty and descemet stripping automated endothelial keratoplasty

PURPOSE

To compare objective and subjective outcomes after Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) in the fellow eye of the same patients.

STUDY DESIGN

Single-center, retrospective case series.

METHODS

Seventeen patients with bilateral Fuchs endothelial dystrophy who underwent DSAEK earlier in 1 eye, and later underwent DMEK in the contralateral eye, composed study population. A chart review was completed to obtain follow-up data for at least 6 months after each surgery. Outcome measures included best spectacle-corrected visual acuity (BSCVA) and endothelial cell density (ECD). Subjective questionnaires were used to assess patients' satisfaction.

RESULTS

Preoperative BSCVA (logMAR) was similar in both groups, 0.66 ± 0.4 in DMEK and 0.59 ± 0.4 in DSAEK (P = .6). The DMEK group showed better BSCVA than the DSAEK group at the 6-month time point (0.25 ± 0.1 and 0.39 ± 0.1, for DMEK and DSAEK, respectively, P = .02). Preoperative ECD (cells/mm(2)) was similar in both groups (2647 ± 249 and 2768 ± 404, P = .3) in DMEK and DSAEK, respectively. There was statistically significant difference found in ECD at 6 months (2227 ± 565 for DMEK and 1780 ± 433 for DSAEK, P = .049). Subjective level of average satisfaction after DMEK was 6 and after DSAEK was 4.87 ± 1.19 (P = .002).

CONCLUSIONS

DMEK provided better visual outcome and lower endothelial cell loss than DSAEK and a higher level of patient satisfaction when assessed at 6 months after surgery. Our results comparing the 2 procedures in the same patients support the benefits of DMEK, and suggest the need for long-term studies observing this new surgical procedure.

Relapsing migratory idiopathic orbital inflammation: six new cases and review of the literature

AIMS

To present a case series of relapsing migratory idiopathic orbital inflammation.

PATIENTS AND METHODS

Case series and review of the literature. The medical records of six patients with recurrent orbital myositis or idiopathic inflammation at different sites treated at the Goldschleger Eye Institute between April 2006 and December 2009 were collected and analysed; one patient treated at the orbital service in Priyamvada Birla Aravind Eye Hospital, Kolkata, India, was also included (June 2008 to August 2010). Orbital biopsy was performed in patients who failed to respond to steroids treatment.

RESULTS

A total of six patients with recurrent episodes of orbital myositis or inflammation were identified. Four patients had orbital myositis of one extraocular muscle at the initial episode and recurrent myositis of a different extraocular muscle on the contralateral orbit. One patient had recurrent myositis of a different extraocular muscle on the same orbit. Two patients had a third episode of recurrence on a different site, that is, an extraocular muscle or an eyelid. One patient had eyelid and soft tissue involvement on one orbit and recurrence of orbital myositis on the contralateral eyelid. Histological findings in the latter case showed small perivascular lymphocytic aggregates and scattered histiocytes. The mean time for recurrence was 7.2 months. All patients were treated successfully with oral steroids and/or intralesional triamcinolone injection.

CONCLUSIONS

Idiopathic orbital inflammation or orbital myositis can recur on a different extraocular muscle and on the contralateral orbit. These cases can be successfully treated with orally administered or intralesionally injected steroids.